Structure and function of the bacterial primosome

描述（由申请人提供）：DNA复制重启途径将DNA复制机制重新加载到由于基因组损伤而被放弃的复制叉上。这些途径在断裂的复制叉的修复（通常是重组修复）和DNA复制之间形成了重要的生化联系。驱动这些反应的蛋白质，被称为primosome或Replication Restart proteins (rrp)，必须识别这些被遗弃的复制叉的结构，并在这些位点重新装载DNA复制机制。这一过程受到严格监管，以确保装载保真度，并避免在不适当的DNA结构上启动复制可能导致的过度复制。这个

DESCRIPTION (provided by applicant): The DNA replication restart pathways reload the DNA replication machinery onto replication forks that have been abandoned as a consequence of genomic damage. These pathways form an essential biochemical link between repair (often recombinational repair) of broken replication forks and DNA replication. The proteins that drive these reactions, referred to as the primosome or the Replication Restart Proteins (RRPs), must recognize the structures of these abandoned replication forks and reload the DNA replication machinery at these sites. This process is heavily regulated to ensure loading fidelity and to avoid over-replication that could arise from initiating replication at improper DNA structures. The structural mechanisms underlying DNA replication restart and the cellular mechanisms by which it is integrated with other cellular genome maintenance processes are currently poorly understood. Our proposal combines structural, biochemical, and genetic approaches to define the mechanisms of DNA replication restart pathways in complementary ways. We wil use X- ray crystallography to determine the crystal structures of key proteins and protein complexes that comprise the primosome (Aim 1). These studies will produce molecular models that will help define the physical mechanisms by which bacterial RRPs function. Additionally, we will define biochemically how RRPs interact with one another to drive replication restart (Aim 2). This set of experiments will link the physical models generated in Aim 1 to steps along the replication restart pathways, to reveal how the primosome ties replication fork recognition to RRP complex assembly. Finally, we will identify linkages that coordinate replication restart with DNA replication, recombination, and repair processes in bacterial cells (Aim 3). These connections will help define how replication restart is integrated into the basal genome maintenance network in cells and how its use is regulated to prevent unwarranted replication initiation. PUBLIC HEALTH RELEVANCE: DNA replication restart is an important process to study from a human health perspective because knowing more about DNA replication will help to identify targets to kill selectively the deleterious, malignant or disease causing cells that may plague our bodies (e.g., tumors or pathogenic organisms). Conversely, this knowledge may also be used to augment the basic health and longevity of our cells. This may be translated into a longer, healthier life for the individual.